The major efforts of our group at present are directed at studies on the molecular level into the life cycle of the human immunodeficiency viruses (HIV), especially type 1. The following areas are addressed: (1) analyses of the viral regulatory genes, especially tat and rev, their interactions with cellular factors which influence their activity, and their effects on expression of cellular genes; (2) studies on the regulation of viral RNA polymerase promoters in different cell types; (3) studies on the regulation of viral gene expression at the level of RNA splicing in different cell types, in different diseases and their stages of progression, and under the influence of extrinsic factors such as cytokines; (4) correlation of proviral structures and integration status with viral gene expression; and (5) development of antiviral treatments based on the above studies.